I attached a Jitterbug from a Seagate 8 TB HD into a Cambridge Audio 851N streamer and heard an immediate improvement. The sound seemed warmer and less harsh. I was not using an audiophile grade USB cable, so I'm not sure if that made a difference. For my money, it was worth the $69, and added one to my car a short time later with satisfying results.
I've recently added the Audioquest Diamond USB 3.0 to the connection from the HD to the 851N and have not yet tried adding the Jitterbug. I'm still reveling in the dramatic difference in the sound that the Diamond cable made to my system.